Who is behind the apparently concerted campaign to smear The New Yorker’s Jane Mayer?

For several weeks, the Daily Caller, a conservative Web site — co-founded by Tucker Carlson and Neil Patel, a former aide to former vice president Dick Cheney — have had a reporter poking around what they thought would be a scandalous story about Mayer.

The allegations were serious — that Mayer borrowed or plagiarized from a liberal blogger and other mainstream publications for an Aug. 30 smackdown in The New Yorker on the conservative billionaire brothers Charles and David Koch. In the end, even the Daily Caller found the allegations to be unfounded, and to its credit, abandoned the story.

The story is dead but the person or persons behind the allegations remains a shadowy mystery.

New Yorker Editor-In-Chief David Remnick said, “Everyone agrees there’s no story here, and we’re baffled by why someone would go through almost 10 years of articles when no one has ever raised ethical questions about Jane’s reporting. It seems like someone is trying to stir up trouble where none exists.”

Mayer’s piece last summer, titled “Covert Operations,” left plenty for the billionaire Koch brothers to be furious about. Aside from family feuds and dirty laundry, it detailed how the brothers, who control Koch Industries — the second-largest privately held company in America, with sales estimated at $100 billion — were also backers of a wide network of conservative think tanks and groups that helped spawn the Tea Party revolution as part of long-running campaign to push the US to the right.

The allegation that Mayer borrowed or plagiarized for the story did not hold water. Indeed, the people who should have been most outraged by the allegations dismissed the claims and were actually supportive of Mayer’s work.

Blogger Lee Fang‘s work was allegedly pilfered by Mayer for The New Yorker piece, according to the bones of the journalistic evidence allegedly passed along to the Daily Caller, which were obtained by Media Ink. Fang, however, was far from upset.

Instead, Fang was supportive of Mayer when Media Ink called. “These accusations are absolutely without merit,” said Fang. “I spoke with Jane Mayer in addition to at least half a dozen other traditional media reporters in the last year about my research on the Koch brothers,” said Fang. “Jane Mayer properly credited me in her story. She clearly did a ton of her own research. I have nothing but admiration for her integrity as a journalist.”

There was also a second allegation forwarded to Daily Caller: that Mayer, way back in 2002, had done a story on accounting regulations and SEC chief Arthur Levitt, drawing heavily from a BusinessWeek cover story that ran in 2000. That allegation also appeared to dis solve under scrutiny.

“I don’t think there is anything to it,” said Paula Dwyer, a main writer of the Levitt cover story who now runs the Washington, DC, of fice for Bloomberg Businessweek. “I would remember if I thought I was plagiarized,” she said. “I remember reading her story at the time, and I think she did a good job.”

On Monday, Carlson told Media Ink that Daily Caller had yet to contact the New Yorker.

We asked if the story would be a right-wing salvo to answer what was perceived to be a left-wing hit directed by The New Yorker and Mayer against the Koch brothers.

He responded: “It’s a bigger story than that. From what I know at this point, it’s an extensive piece.”

Carlson said he expected to post the story “sometime later this week.” The reporter on the story was Jonathan Strong, he said.

By yesterday, Strong had indeed called The New Yorker, but told Remnick the Daily Caller was not doing the story after all. Carlson was also calling Media Ink around that time to tell us, as well, that the Daily Caller had dropped the story. Carlson said he did not know the origin of the allegations against Mayer. “I have no clue where we got it. I never ask the reporters where they get stuff, only whether it’s true. In this case, we didn’t have enough.”

Strong declined to comment.

Carlson is a senior fellow at the Cato Institute, which has strong ties to the Koch brothers al though a spokeswoman insisted those ties have diminished lately and that co-founder Charles Koch, who pumped tens of millions into the group over the years, had cut back in 2009 and withdrew funding entirely in 2010. David Koch remains on its board.

The spokeswoman for Cato said she had no direct dealing with the Koch brothers and suggested we call Koch Industries. A spokeswoman for Koch Industries had not answered our e-mailed questions by presstime.

Muted Voice

It’s the end of an era at the Village Voice, as two of its best-known columnists, Wayne Barrett — a 30-year veteran and its chief political investigative reporter — and Tom Robbins, its star metro columnist who punctuated his two stints at the alternative weekly with a stretch at the Daily News — have both packed it in.

Barrett, in a posting on the Voice Web site, reminisced how both he and Ed Koch were inaugurated on the same day that he took over the Runnin’ Scared column in January 1978. He also said that Robbins, the paper’s union representative, worked on Barrett’s exit package but kept quiet until the end about his own plans to leave.

Barrett said that Robbins told him, “I’m going out with the guy who brought me to the dance.” Robbins’ resignation is effective at the end of the month. Barrett was apparently gone last week, but his farewell was on the Village Voice Web site yesterday.

In his career, he said, he has written more column inches than anyone in the history of the Village Voice. “These will be my last.”

Robbins said he plans to “keep doing what I’ve always done, comfort the afflicted and afflict the comfortable — maybe in books, articles or on Broadway.”

HuffPo suit

There is a lawsuit against the Huffington Post and founders Arianna Huffington and Ken Lerer that is the subject of an article in the new issue of Vanity Fair. In it, William D. Cohan writes that the two plaintiffs, James Boyce and Peter Daou, claim that they were the ones who came up with the original idea for a “liberal Drudge Report” and drew up a position paper that Huffington presented to a room full of well-connected individuals at her Brentwood, Calif., home in the days after John Kerry‘s defeat in the 2004 presidential election.

Huffington Post recently said it was profitable and is believed to have annual revenue of around $20 million to $25 million. According to an exclusive interview with Cohan, Daou and Boyce claim that they gave Huffington a detailed memo for a site to be called 1460 — which is the exact number of days between presidential elections — and it eventually evolved into the Huffington Post.

The two claim they waited six years to file the suit because the Huffington Post was like family and because they had grown tired of Huffington and Lerer citing the meeting as the touchstone for the Web site without giving them credit. They also said they were angry that An drew Breitbart, a conservative blogger who did a short stint at the Huffington Post, claimed to be the founder.

Arianna isn’t buy ing it. In an e-mail back to them, she replied, “Your suggestion after six years that you understood all along that we were in a ‘partnership’ to create and operate the Huffington Post is stunning. And ridiculous.” kkelly@nypost.com